ICES Advice on fishing opportunities, catch, and effort Baltic Sea ecoregion Published 28 May 2021
Herring (Clupea harengus) in Subdivision 28.1 (Gulf of Riga)
ICES advice on fishing opportunities ICES advises that when the EU multiannual plan (MAP) for the Baltic Sea is applied, the catches in 2022 that correspond to the F ranges in the plan are between 34 797 tonnes and 52 132 tonnes. According to the MAP, catches higher than those corresponding to FMSY (44 945 tonnes) can only be taken under conditions specified in the plan, whilst the entire range is considered precautionary when applying ICES advice rule. This advice applies to all catches from the stock in subdivisions 28.1 and 28.2.
Stock development over time
Fishing pressure on the stock is below FMSY and spawning-stock size is above MSY Btrigger, Bpa, and Blim.
Figure 1 Herring in Subdivision 28.1. Summary of the stock assessment. The assumed recruitment for 2021 is shaded in a lighter colour. SSB at spawning time in 2021 is predicted.
Catch scenarios
Table 1 Herring in Subdivision 28.1. Assumptions made for the interim year and in the forecast. Variable Value Notes Fages 3–7 (2021) 0.24 F based on catch constraint SSB (2021) 176560 Projected SSB at spawning time; tonnes 3243312 Geometric mean of year classes 1989– Rage 1 (2021–2023) 2018; thousands Total catch (2021) 35 771 Catch constraint of 35 771 tonnes* * Catch constraint in 2021: TAC for Gulf of Riga management area (39 446 tonnes) + Gulf of Riga herring caught in the central Baltic (514 tonnes) − central Baltic herring caught in the Gulf of Riga (4189) tonnes = 35 771 tonnes.
ICES Advice 2021 – her.27.28 – https://doi.org/10.17895/ices.advice.7768 ICES advice, as adopted by its Advisory Committee (ACOM), is developed upon request by ICES clients (European Union, Iceland, NASCO, NEAFC, Norway, and United Kingdom). 1 ICES Advice on fishing opportunities, catch, and effort Published 28 May 2021 her.27.28
Table 2 Herring in Subdivision 28.1. Annual catch scenarios. All weights are in tonnes. Total catch % Advice change Basis F (2022) SSB (2022) SSB (2023) % SSB change ** (2022) *** ICES advice basis EU MAP *: FMSY 44 945 0.32 167 666 147 612 −12% 26%
EU MAP *: Flower 34 797 0.24 170 010 158 979 −6.5% 26%^ EU MAP *: Fupper 52 132 0.38 165 931 139 671 −16% 26%^^ Other scenarios FMSY 44 945 0.32 167 666 147 612 −12% 26% F = 0 0 0 177 244 199 221 12% −100% F = Fpa 52 132 0.38 165 931 139 671 −16% 46% F = Flim 100 226 0.88 152 173 89 128 −41% 180% Advice for 2022 limited by +20% § 42 925 0.30 168 143 149 861 -11% 20% SSB (2023) = SSB (2022) 21 992 0.146 172 805 173 567 0.44% −39% SSB (2023) = Blim 152 363 1.81 129 575 40 800 −69% 326% SSB (2023) = Bpa 133 758 1.40 139 098 57 100 −59% 274% SSB (2023) = MSY Btrigger 130 579 1.34 140 527 60 000 −57% 265% F = F2021 35 242 0.24 169 909 158 477 −6.7% −1.48% * MAP multiannual plan (EU, 2016). ** SSB 2023 relative to SSB 2022. *** Total catch in 2022 relative to ICES advice for 2021 (35 771 tonnes for the Gulf of Riga herring stock). ^ ICES advice for Flower for 2022 relative to ICES advice for Flower for 2021 (27 702 tonnes). ^^ ICES advice for Fupper for 2022 relative to ICES advice for Fupper for 2021 (41 423 tonnes). § Advised catch given for 2022 limited by a 20% increase .
The catch advice for 2022 is higher due to the strong 2019 year class.
Basis of the advice
Table 3 Herring in Subdivision 28.1. The basis of the advice. Advice basis EU Baltic multiannual plan The EU multiannual plan (MAP) in place for stocks in the Baltic Sea includes herring (EU, 2016, 2019). Management plan The advice based on the FMSY ranges used in the management plan is considered precautionary.
Quality of the assessment
Historical assessments have generally shown an overall upward revision in SSB and a downward revision in fishing mortality. The reasons for both these trends are not fully understood.
Figure 2 Herring in Subdivision 28.1. Historical assessment results. (Recruitment in the final year is based on a geometric mean assumption.)
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Issues relevant for the advice
The assessment and the advice take account of all of the Gulf of Riga herring stock, both that harvested in the Gulf of Riga and that harvested outside of it. The TAC proposed for the Gulf of Riga area is based on the advised catch for the Gulf of Riga herring stock, plus the assumed catch of central Baltic herring harvested in the Gulf of Riga, minus the assumed catch of Gulf of Riga herring taken outside the Gulf of Riga. The values of the two latter are given by the average over the last five years.
1. Central Baltic herring assumed to be taken in the Gulf of Riga in 2022 (Subdivision 28.1) is 3448 tonnes (average 2016–2020). 2. Gulf of Riga herring assumed to be taken in Subdivision 28.2 in 2022 is 696 tonnes (average 2016–2020).
As an example, following ICES MSY approach (here identical to the MAP FMSY), catches from the Gulf of Riga herring stock in 2022 should be no more than 44 945 tonnes. The corresponding TAC in the Gulf of Riga management area for 2022 would be calculated as: 44 945 tonnes – 696 tonnes + 3448 tonnes = 47 697 tonnes.
Reference points
Table 4 Herring in Subdivision 28.1. Reference points, values, and their technical basis. Weights in tonnes. Framework Reference point Value Technical basis Source
MSY Btrigger 60 000 From stock–recruitment relationship ICES (2009, 2015) Stochastic simulations with Beverton, Ricker, and MSY approach FMSY 0.32 segmented regression stock–recruitment model from ICES (2015) the full time-series (1977–2013) Blim 40 800 Blim = Bloss ICES (2015) Bpa = Blim × exp(σ × 1.645) with the default value Precautionary Bpa 57 100 ICES (2015) σ = 0.2. approach Flim 0.88 Flim derived from the curve of SSB/R against F ICES (2015) Fpa 0.38 FP05. The F that leads to SSB ≥ Blim with 95% probability ICES (2021a) EU (2016 – MAP MSY B 60 000 MSY B trigger trigger Annex II column A) EU (2016 – MAP B Not defined lim Annex II column B) EU (2016 – Annex I MAP F 0.32 F Management MSY MSY columns A and B) plan Consistent with the ranges provided by ICES (2015), ICES (2015) and MAP target 0.24–0.32 resulting in no more than 5% reduction in long-term EU (2016 – Annex I range F –F lower MSY yield compared with MSY column A) Consistent with the ranges provided by ICES (2015), ICES (2015) and MAP target 0.32–0.38 resulting in no more than 5% reduction in long-term EU (2016 – Annex I range F F MSY– upper yield compared with MSY column B)
Basis of the assessment
Table 5 Herring in Subdivision 28.1. Basis of the assessment and advice. ICES stock data category 1 (ICES, 2021b) Assessment type Age-based analytical assessment XSA (ICES, 2021a) that uses catches in the model and in the forecast Commercial catches; one acoustic survey index (GRAHS, A2217); one commercial CPUE index (trapnets); Input data fixed maturity ogive; natural mortality is assumed to be constant at 0.2 for all years except 1979–1983, when it was 0.25 Discards and bycatch Not included, considered negligible Indicators None Other information The latest benchmark was performed in 2008 (ICES, 2008) Working group Baltic Fisheries Assessment Working Group (WGBFAS)
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History of the advice, catch, and management
Table 6 Herring in Subdivision 28.1. ICES advice, TAC for the Gulf of Riga, and catches of Gulf of Riga herring stock from the Gulf of Riga. All weights are in tonnes. Catch from stock corresp. Agreed TAC for Gulf of Catches of Gulf of Riga Year ICES advice to advice Riga herring stock 1987 Reduce F towards F0.1 8000 - 12884 1988 Reduce F towards F0.1 6000 - 16791 F should not exceed 1989 20000 - 16783 present level F should not exceed 1990 20000 - 14931 present level No separate advice for 1991 - - 14791 this stock No separate advice for 1992 - - 20000 this stock No separate advice for 1993 - - 22200 this stock No separate advice for 1994 - - 24300 this stock No separate advice for 1995 - - 32656 this stock No separate advice for 1996 - - 32584 this stock Current exploitation rate 1997 within safe biological 35000 - 39843 limits Current exploitation rate 1998 within safe biological 35000 - 29443 limits Current exploitation rate 1999 within safe biological 34000 - 31403 limits Current exploitation rate 2000 within safe biological 37000 - 34069 limits Current exploitation rate 2001 within safe biological 34100 - 38785 limits Current exploitation rate 2002 within safe biological 33200 - 39701 limits 2003 F below Fpa < 41000 41000 40803 2004 F = Fsq 39000 39300 39115 2005 F = Fsq 35300 38000 32225 2006 F = Fpa 39900 40000 31232 2007 F = Fpa 33900 37500 33742 2008 F < Fpa < 30100 36100 31137 2009 F < Fpa < 31500 34900 32554 2010 F < Fpa < 33400 36400 30174 2011 F < Fpa < 33000 32700 29639 2012 MSY transition < 25500 30600 28115 2013 MSY framework < 23200 30600 26511 2014 MSY < 25800 30700 26253 2015 MSY (FMSY = 0.35) < 34300 38800 32851 MSY approach 2016 ≤ 26200 34900 30865 (FMSY = 0.32) MSY approach 2017 ≤ 23100 31100 28058 (FMSY = 0.32)
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Catch from stock corresp. Agreed TAC for Gulf of Catches of Gulf of Riga Year ICES advice to advice Riga herring stock MAP target F ranges: Flower to Fupper (0.24– 19396–29195, but catch 0.38), but F higher than higher than 24919 only 2018 28999 25747 FMSY = 0.32 only under under conditions conditions specified in specified in the MAP the MAP MAP target F ranges: Flower to Fupper (0.24– 20664–31237, but catch 0.38), but F higher than higher than 26932 only 2019 31044 28922 FMSY = 0.32 only under under conditions conditions specified in specified in the MAP the MAP MAP target F ranges: Flower to Fupper (0.24– 23395–35094, but catch 0.38), but F higher than higher than 30382 only 2020 34445 33215 FMSY = 0.32 only under under conditions conditions specified in specified in the MAP the MAP 35771 (ranges 27702– 2021 Management Plan 39446 41423) 44945 (range 34797- 2022 Management Plan 52132)
History of the catch and landings
Table 7 Herring in Subdivision 28.1. Catch distribution by fleet in 2020 as estimated by ICES. Total herring catch in the Gulf of Riga Total catch of stock Landings Discards management area (2020) (2020) Trawls 79% Trapnets 21% Discarding is considered 33249 tonnes 33215 tonnes 33215 tonnes to be negligible
Table 8 Herring in Subdivision 28.1. ICES estimates of total catches of herring in the Gulf of Riga by country. All weights are in tonnes. Year Estonia Latvia Unallocated landings Total 1991 7410 13481 - 20891 1992 9742 14204 - 23946 1993 9537 13554 2209 25300 1994 9636 14050 3514 27200 1995 16008 17016 3332 36356 1996 11788 17362 3534 32684 1997 15819 21116 4308 41243 1998 11313 16125 3305 30743 1999 10245 20511 3077 33803 2000 12514 21624 2631 36769 2001 14311 22775 3399 40485 2002 16962 22441 3398 42801 2003 19647 21780 3276 44703 2004 18218 20903 3094 42215 2005 11213 19741 3071 34025 2006 11924 19186 2922 34032 2007 12764 19425 2953 35142 2008 15877 19290 1970 37137 2009 17167 18323 1864 37354 2010 15422 17751 1791 34974 2011 14721 20218 - 35039 2012 13789 17926 - 31715 2013 11898 18413 - 30311
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Year Estonia Latvia Unallocated landings Total 2014 10541 20012 - 30553 2015 16509 21010 - 37519 2016 15814 19066 - 34880 2017 13772 17948 - 31720 2018 12521 16904 - 29424 2019 13320 17961 - 31281 2020 12231 21019 - 33249
Table 9 Herring in Subdivision 28.1. Total catches (in tonnes) in the Gulf of Riga by stock and of the Gulf of Riga herring stock by area. Catches in the Gulf of Riga Gulf of Riga herring catches Year Gulf of Riga Central Baltic Total In the central Baltic Total herring herring 1977 24186 2400 26586 - 24186 1978 16728 6300 23028 - 16728 1979 17142 4700 21842 - 17142 1980 14998 5700 20698 - 14998 1981 16769 5900 22669 - 16769 1982 12777 4700 17477 - 12777 1983 15541 4800 20341 - 15541 1984 15843 3800 19643 - 15843 1985 15575 4600 20175 - 15575 1986 16927 1300 18227 - 16927 1987 12884 4800 17684 - 12884 1988 16791 3000 19791 - 16791 1989 16783 5900 22683 - 16783 1990 14931 6000 20931 - 14931 1991 14791 6100 20891 - 14791 1992 18700 3500 23946 1300 20000 1993 21000 4300 25300 1200 22200 1994 22200 5000 27200 2100 24300 1995 30256 6100 36356 2400 32656 1996 28284 4400 32684 4300 32584 1997 36943 4300 41243 2900 39843 1998 26643 4100 30743 2800 29443 1999 29503 4300 33803 1900 31403 2000 32169 4600 36769 1900 34069 2001 37585 2900 40485 1200 38785 2002 39301 3500 42801 400 39701 2003 40403 4300 44703 400 40803 2004 38915 3300 42215 200 39115 2005 31725 2300 34025 500 32225 2006 30832 3200 34032 400 31232 2007 33642 1500 35142 100 33742 2008 31037 6100 37137 100 31137 2009 32454 4900 37354 100 32554 2010 29774 5200 34974 400 30174 2011 29539 5500 35039 100 29639 2012 27915 3800 31715 200 28115 2013 26211 4100 30311 300 26511 2014 26053 4500 30553 200 26253 2015 32551 4968 37519 316 32851 2016 30565 4315 34880 289 30865 2017 27824 3896 31720 234 28058 2018 25217 4208 29424 530 25747 2019 27721 3560 31281 1200 28922 2020 31986 1264 33249 1229 33215
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Summary of the assessment
Table 10 Herring in Subdivision 28.1. Assessment summary. Weights are in tonnes; recruitment in thousands. Year Recruitment (age 1) SSB* Catches F (ages 3–7) 1977 943222 54522 24186 0.69 1978 1076482 49356 16728 0.38 1979 976944 46739 17142 0.43 1980 1110340 46712 14998 0.35 1981 908421 47221 16769 0.45 1982 1689000 42758 12777 0.42 1983 1253653 50858 15541 0.47 1984 2027213 39914 15843 0.71 1985 1388054 51937 15575 0.54 1986 1120343 64284 16927 0.51 1987 3928624 51522 12884 0.42 1988 560967 96701 16791 0.52 1989 1292385 63293 16783 0.36 1990 3645492 77332 14931 0.24 1991 3689914 87277 14791 0.25 1992 4319311 106141 20000 0.27 1993 3257248 120787 22200 0.23 1994 2788376 124965 24300 0.23 1995 3469542 116708 32656 0.34 1996 4668037 105795 32584 0.36 1997 1598978 103574 39843 0.49 1998 2763269 82140 29443 0.43 1999 2897394 84194 31403 0.42 2000 2645554 84025 34069 0.45 2001 6088728 79443 38785 0.52 2002 2291719 101021 39701 0.46 2003 7172071 86918 40803 0.53 2004 1034657 93406 39115 0.58 2005 3216351 75411 32225 0.49 2006 7116258 73416 31232 0.42 2007 2057771 95052 33742 0.52 2008 5641770 95083 31137 0.29 2009 2874764 112381 32554 0.35 2010 2915262 106631 30174 0.28 2011 1188641 108524 29639 0.32 2012 5724457 94730 28115 0.29 2013 6072780 118689 26511 0.22 2014 1164668 143791 26253 0.23 2015 2619073 128582 32851 0.30 2016 4314619 114876 30865 0.29 2017 3179703 123092 28058 0.25 2018 6193234 124599 25747 0.21 2019 2988617 143579 28921 0.26 2020 7101760 146956 33215 0.24 2021 3243312** 176560*** * At spawning time. ** Geometric mean of year classes 1989–2018. *** Predicted.
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Sources and references EU. 2016. Regulation (EU) 2016/1139 of the European Parliament and of the Council of 6 July 2016 establishing a multiannual plan for the stocks of cod, herring and sprat in the Baltic Sea and the fisheries exploiting those stocks, amending Council Regulation (EC) No 2187/2005 and repealing Council Regulation (EC) No 1098/2007. Official Journal of the European Union, L 191, 15.7.2016. 15 pp. http://data.europa.eu/eli/reg/2016/1139/oj. EU. 2019. Regulation (EU) 2019/472 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 19 March 2019 establishing a multiannual plan for stocks fished in the Western Waters and adjacent waters, and for fisheries exploiting those stocks, amending Regulations (EU) 2016/1139 and (EU) 2018/973, and repealing Council Regulations (EC) No 811/2004, (EC) No 2166/2005, (EC) No 388/2006, (EC) No 509/2007 and (EC) No 1300/2008. Official Journal of the European Union, L 83, 25.3.2019. 17 pp. http://data.europa.eu/eli/reg/2019/472/oj. ICES. 2008. Report of the Baltic Fisheries Assessment Working Group (WGBFAS), 8–17 April 2008, ICES Headquarters, Copenhagen, Denmark. ICES CM 2008\ACOM:06. 692 pp. ICES. 2009. Workshop on Multiannual Management of Pelagic Stocks in the Baltic, 23–27 February 2009, ICES Headquarters, Copenhagen. ICES CM 2009/ACOM:38. 126 pp.
ICES. 2015. EU request to ICES to provide FMSY ranges for selected North Sea and Baltic Sea stocks. In Report of the ICES Advisory Committee, 2015. ICES Advice 2015, Book 6, Section 6.2.3.1. 11pp. https://www.ices.dk/sites/pub/Publication%20Reports/Advice/2015/Special_Requests/EU_FMSY_ranges_for_selected_ NS_and_BS_stocks.pdf. ICES. 2021a. Baltic Fisheries Assessment Working Group (WGBFAS). ICES Scientific Reports, 3:53. 717 pp. http://doi.org/10.17895/ices.pub.8187 ICES. 2021b. Advice on fishing opportunities. In Report of the ICES Advisory Committee, 2021. ICES Advice 2021, section 1.1.1. https://doi.org/10.17895/ices.advice.7720.
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Recommended citation: ICES. 2021. Herring (Clupea harengus) in Subdivision 28.1 (Gulf of Riga). In Report of the ICES Advisory Committee, 2021. ICES Advice 2021, her.27.28. https://doi.org/10.17895/ices.advice.7768.
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